There are many sealed electrical terminals currently available but none of them addresses the seals for simultaneous high-current, high-pressure, low-inductance, and high-reliability features. For example, there are millions of hermetic electrical compressors that use Kovar-clad copper terminals for relatively low current (less than 100 amperes) operations. For the high current terminals such as the Paul Clifford's “Fire-Proof Seals” of U.S. Pat. No. 5,091,605, Feb. 25, 1992 which presented “a fire proof seal for a tubular conduit (16) of thermally conductive material adapted to contain an elongated member (24) extending axially outside the conduit, the seal comprising a thermally conductive sleeve (34) surrounding the member externally of the conduit and in thermal contact with an external flange (40) of the conduit, and a thermally fusible material (30) surrounding the member within the conduit, whereby, in the event of a fire in the vicinity of the member externally of the conduit, heat is transmitted through the sleeve into the conduit so as to fuse the thermally fusible material and block the interior of the conduit”. Clifford's invention does not function during normal service conditions because his seal is only formed by the heat during a fire. Furthermore, this fire-triggered seal is not suitable for high-pressure difference across the seal other than the pressure difference caused by the fire, which is very low as compared to the high-pressure that can easily reach several hundred pounds per square inch in pressure vessel seals.
Because the high-pressure liquid and vapor inside the hermetic container are not allowed to leak out through the high-pressure, high-electrical-current terminals under a wide range of temperatures, the seal must be extremely reliable at all times. Another problem with the existing sealed terminals is the high flux leakage reactance. Because of the high currents going through the terminals, the magnetic flux links the conductors. Consequently, the magnetic flux produces leakage reactance that can harm the performance of the electrical circuit connected to the terminals. Thus, there is a defined need for sealed terminal assembly technology simultaneously meeting the high-pressure, high-electric-current, low-inductance, and high-reliability requirements.